Cascading style sheets (CSS) provide web site developers with control over the visual appearance, style (e.g., size, color, font, margins, etc.), and positioning of text in web pages without compromising the structure of the page. Developers may use CSSs to create templates for attaching style rules to structured documents (e.g., hypertext markup language (HTML) documents and extensible markup language (XML) applications). CSSs separate the presentation style of documents from the content of the documents thereby simplifying web authoring and site maintenance. CSSs may include instructions in the code of a web site that describe how a browser should render any instance of a particular element on a page. For example, style sheets can provide instructions for how all of the hypertext, headers, links, or text should appear.